|  |  | 
|  | FREERTOS COLDFIRE MCF523x PORT with lwIP | 
|  |  | 
|  | REQUIREMENTS | 
|  | ============ | 
|  |  | 
|  | The FreeRTOS port is designed for the MCF523x processor where the hardware | 
|  | dependent part consists of the CPU and the peripherals used in this  port. | 
|  | This includes a programmable timer  (PIT)  for  the  preemptive  scheduler | 
|  | and a UART for the demo application.  The Coldfire specific part  includes | 
|  | the number and type of processor registers, the  stack  frame  layout  and | 
|  | the usage of a software interrupt (trap) for the yield call. | 
|  |  | 
|  | The development environment used is  based  on  the  GNU  C  Compiler  for | 
|  | a m68k-elf target as well as the insight debugger with  some  patches  for | 
|  | the BDM interface[1].  GDB startup and linker scripts  are  supplied  with | 
|  | the demo for the M5235BCC evaluation kit from Freescale. | 
|  |  | 
|  | [1] ... BDM tools: http://sourceforge.net/projects/bdm/ | 
|  |  | 
|  | USAGE | 
|  | ===== | 
|  |  | 
|  | A makefile is supplied with the demo  application  and  a  binary  can  be | 
|  | produced by calling 'make all'.  A  special  target  'debug'  is  provided | 
|  | which executes the insight  debugger.   At  the  insight  debugger  prompt | 
|  | one should select the  appropriate  target  interface  (either  BDM/Direct | 
|  | or BDM/TCP)  and  should  download  the  application  to  the  development | 
|  | board.  It is important that the GDB  script  setup-and-load  is  executed | 
|  | prior to downloading to  initialize  the  SDRAM.   After  downloading  one | 
|  | should call the GDB function 'execute' and the PC  is  set  to  the  start | 
|  | of the executable.  Execution can  be  started  by  typing  'continue'  at | 
|  | the Insight console interface. | 
|  | After this  startup phase the  insight debugger should work as usual, i.e. | 
|  | no grayed out buttons, ... | 
|  |  | 
|  |  | 
|  | COMMON PROBLEMS | 
|  | =============== | 
|  |  | 
|  | Most of the problems have  their  origin  in  the  startup  scripts.   The | 
|  | following list should serve as  a  checklist  where  each  point  must  be | 
|  | satisfied for the port to work. | 
|  |  | 
|  | - The FreeRTOS port only works correctly in the supervisor mode.   There- | 
|  | fore the Coldfire CPU must run in the supervisor mode. | 
|  |  | 
|  | - portVECTOR_TABLE does not point to the currently active  vector  table. | 
|  | Please also note that the vector table must be in  RAM  such  that  the | 
|  | FreeRTOS port can install a traphandler for the portYIELD() call. | 
|  |  | 
|  |  | 
|  | $Id: README.txt,v 1.1 2006/08/29 02:24:03 wolti Exp $ | 
|  |  | 
|  | MCF5235 + lwIP port - Copyright (c) 2006 Christian Walter. | 
|  |  |